As technology advances, mobile electronic devices are becoming more and more popular. For example, smartphones, tablet computers, and notebook computers play an important role in the lives of modern people. Mobile electronic devices are usually supplied with power by their batteries. Nowadays, people prefer batteries with large capacity, but it has become a critical challenge to charge large-capacity batteries in a short time. Generally speaking, a conventional charger uses only one charging path to charge a battery, and such a design has disadvantages, such as a long charging time, thermal effects, and insufficient charging capabilities. As a result, there is a need to design a novel charger to overcome the problems of the prior art.